It's not strange that insurers won't 'cover' vaccine liability. Instead, there is vaccine liability fund, funded by the manufacturers and congress to compensate anyone who claims to be harmed by a vaccine. It's set up similar to a workman's compensation scheme. If you think you were harmed, you file for compensation from the fund without the burden of proving the vaccine was unreasonably dangerous. It's a win across the board because 1 ) manufacturers are not at risk of simple liability, and are therefore more likely to invest in what is generally a terrible business model 2) people harmed have a streamlined path to compensation, and 3) you don't have multiple high-profile cases that muddy the waters around vaccine safety, So, it's not strange that Pfizer wouldn't be individually insured against vaccine liability. That said, there is a lot of daylight between an MMR vaccine using attenuated viruses that has been around for 70 years and used on hundreds of millions of people, and a vaccine using a novel functionality that was developed in just a few months.